In this paper, we investigate household adaptive responses to extreme heat and the role of electricity infrastructure upgrades in Karachi, Pakistan, one of the ten countries most severely affected by climate-related disasters. Specifically, we ask: How do poor households adjust their electricity usage in response to high temperatures? Do infrastructure upgrades, which were designed to reduce electricity theft, affect electricity usage and losses differently under different temperatures? What are the distributional consequences of the infrastructure improvements on households’ ability to adapt to extreme heat?